Pentacoordinate Co(II) complex based on bulky tridentate and bidentate ligands with field-supported slow magnetic relaxation

IF 2.8 4区化学 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Transition Metal Chemistry Pub Date : 2026-03-03 DOI:10.1007/s11243-026-00723-4

Marek Szabó Dózsa, Richard Smolko, Erika Samoľová, Erik Čižmár, Juraj Černák

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引用次数: 0

Abstract

Reaction of cobalt(II) acetate with neocuproine (neoc, 2,9-dimethyl-1,10-phenantroline) and Schiff base H₂(samphe) (Schiff base formed by condensation of salicylaldehyde with 2-amino-4-methylphenol) afforded complex [Co(neoc)(samphe)] (1) which was chemically and spectroscopically characterized. Crystal structure of 1 is composed of neutral complex molecules in which the Co(II) atom is pentacoordinated and its coordination sphere is formed by one chelating neoc ligand and one tridentate dianionic chelating ligand samphe^2- (ONO-donor). Calculated τ₅ value of 0.435 indicates that the coordination polyhedron can be viewed as an intermediate shape between a square pyramid and a trigonal bipyramid. The complex 1 displays enhanced thermal stability up to 330 °C. The magnetic study of 1 has shown that Co(II) is in a high-spin state S = 3/2 and exhibits easy-axis magnetic anisotropy with parameters D = -48.7 cm^-1 and E/D = 0.166. The AC magnetic study indicates the presence of field-supported slow magnetic relaxation with a maximum of the imaginary component above 10 kHz. The results of the magnetic study are supported by theoretical calculations.

Graphical abstract

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基于大体积三齿和双齿配体的五坐标Co（II）配合物的场支持慢磁弛豫

乙酸钴与新根碱（新根碱，2,9-二甲基-1,10-菲苯啉）和希夫碱H2（水杨醛与2-氨基-4-甲基苯酚缩合而成的希夫碱）反应得到配合物[Co（新根碱）（samphe）](1)，并对其进行了化学和光谱表征。1的晶体结构是由Co（II）原子为五配位的中性络合物分子组成，其配位球由一个螯合新配体和一个三齿二阴离子螯合配体samphe2- （ono -供体）组成。计算出的τ5值为0.435，表明配位多面体可以看作是介于正方形金字塔和三角形双金字塔之间的中间形状。该复合物1显示出高达330°C的增强热稳定性。对1的磁性研究表明，Co（II）处于高自旋态S = 3/2，具有易轴磁各向异性，参数D = -48.7 cm-1, E/D = 0.166。交流磁场研究表明存在场支持的慢磁弛豫，虚分量最大值在10khz以上。磁学研究的结果得到了理论计算的支持。图形抽象

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来源期刊

Transition Metal Chemistry 化学-无机化学与核化学

CiteScore

3.60

自引率

0.00%

发文量

审稿时长

1.3 months

期刊介绍： Transition Metal Chemistry is an international journal designed to deal with all aspects of the subject embodied in the title: the preparation of transition metal-based molecular compounds of all kinds (including complexes of the Group 12 elements), their structural, physical, kinetic, catalytic and biological properties, their use in chemical synthesis as well as their application in the widest context, their role in naturally occurring systems etc. Manuscripts submitted to the journal should be of broad appeal to the readership and for this reason, papers which are confined to more specialised studies such as the measurement of solution phase equilibria or thermal decomposition studies, or papers which include extensive material on f-block elements, or papers dealing with non-molecular materials, will not normally be considered for publication. Work describing new ligands or coordination geometries must provide sufficient evidence for the confident assignment of structural formulae; this will usually take the form of one or more X-ray crystal structures.